ABN Compression Tester and Adapter - 14mm Dual Automotive Compression Gauge with 18mm Compression Tester Adapter

1. It works as described. Unscrew the spark plug and screw this in. 2. The 14mm adapter is threaded so it fits into the 18 mm. Just unscrew the 18 off to use the 14mm. 3. It is very well made and the pressure reading stays until you push the release button.

Fast shipping from the seller. Item arrived on time. I used this particular item to check the compression on my home push mower. This high quality well made product worked flawlessly. And all of this for a most reasonable price.

Not the greatest; it doesn't cover all of the modern spark plug thread sizes, and the location of its check valve (adjacent to the relief button instead of at the tip of the hose) means that it won't work well with small engines like chainsaws and lawn mowers.

This inexpensive compression guage has all rhe accuracy and features of a much more expensive guage, including quick disconnect and interchangeable screw thread sizes. Most importantly, it has a scrader valve at the spark plug screw-in end piece, assuring no loss of accuracy. I measured this guage against my old but hight quality guage on the same chainsaw engine and got exactly the same reading (175 psi) on both guages. Interestingly, I only got 105 PSI when I quick connected either this or my higher quality guage to the tubing from a cheaper compression guage kit that did not have the shrader valve on the business end. I was getting very low readings using that defective old kite and threw the guage away, but kept the hose. Turns out there was also a problem with the hose in that cheap kit as it lacked an authentic shrader valve at the screw-in fitting. Make sure any compression guage hose that you use, has a schrader valve on the threaded end, as well as an air pressure release valve at the indicater end. The cheap guages have only a flap valve and those leak air under pressure. The better guages (including this inexpensive one)l have both an authentic, replacible schrader valve, and a release valve. I saw a utube video describing this and didn’t believe it. But trust me....it makes all the difference in the world.

I used this twice and it worked fine, third time it broke and won't allow me to thread into the spark plug hole because the tube separated from the threads. I would not recommend this

Good product,good price , fast shipping , no reason to leave home. I plan to be a customer for a long time.

I asked Rufus if it had a Schrader valve, and the answer was yes. When I looked at it upon delivery, it had no Schrader Valve.

very poor quality. Fitting also was NOT what I needed.